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Biomedical subjects

C Miguel

Publications and source records attributed to C Miguel.

16 recordsLinked to original sources
PubMed2005

Unequal treatment access and malaria risk in a community-based intervention program in the Philippines.

This study assesses the influence of several malaria risk factors and volunteer health worker (VHW) accessibility on parasite prevalence and treatment-seeking in a remote area of Mindanao, the Philippines. An anti-malaria program in the area seeks to devolve malaria diagnosis and treatment to the VHWs. Firstly, the relationship between malaria and demographic factors, bednet use, and access to treatment was investigated. Secondly, adults from villages with and without resident VHWs were questioned on historical and proposed treatment-seeking for fever and the capacity of the communities to support more health workers was assessed. Parasite prevalence was significantly higher among patients living in villages lacking a resident VHW (adjusted OR=3.88, p=0.02), where proposed delays in consulting VHWs and the official health service, and the use of alternative medicine, were also significantly higher. Kinship or social closeness to VHWs appears to play a role in accessibility. The educational and economic requirements demanded of VHWs impede potential expansion of the program to non-serviced villages. If the effectiveness and equity of community-based treatment strategies is to be increased, increased flexibility allowing use of local, less-educated, drug dispensers needs to be considered.

Adolescent↗
PubMed2003

Metallothionein concentrations in a population of Patella aspera: variation with size.

The determination of metallothionein (MT) concentrations in species with different feeding habits is important from the ecotoxicological point of view because it provides a better understanding of the role of these proteins in metal uptake pathways. The main objective was study the variation of MT and metal (Cd, Cu and Zn) concentrations with size and weight in the limpets Patella aspera. In addition investigate the relationship between MT and metal concentrations in limpets from different metal load environments of the south coast of Portugal with the aim to use MT in P. aspera as a biomarker of metal exposure. MT concentrations in the whole soft tissues of P. aspera increased with size and weight while metals decrease with size and weight. MT concentrations showed no significant relationship with Cd or Cu concentrations in the limpets from the South Portuguese Coast. However, a negative exponential relationship detected between MT and Zn concentrations suggest that Zn bound to MT might be displaced by Cd or Cu ions. The ability of limpets to store both Cd and Cu bound to MT may be responsible for the tolerance of this species to contaminated environments. The relationship between MT concentrations and Zn indicates that MT seems to play a minor role in binding Zn in Patella species.

Adaptation, Physiological↗
PubMed2001

Diagnosis of malaria in a remote area of the Philippines: comparison of techniques and their acceptance by health workers and the community.

OBJECTIVE: To compare the efficacies of remote symptom-based diagnosis of malaria, rapid diagnostic tests and microscopy in an area of low endemicity in the Philippines. METHODS: In Trial I, 350 symptomatic patients were tested within their villages using malaria Plasmodium falciparum (Pf)/Plasmodium vivax (Pv) immunochromatographic tests (ICT tests) and blood films stored and read under local conditions. The slides were later restained and read. In Trial II, unsupervised volunteer barangay health workers prepared ICT tests and slides after brief training. These slides were read at rural health units. Twenty-seven barangay health workers and 72 community members were later questioned about the three diagnostic strategies. FINDINGS: A history of fever alone was sensitive (95.4%) but poorly specific (16.5%) for predicting parasitaemia. The inclusion of other symptoms reduced the sensitivity to below 85%, while specificity remained low. The axillary temperature was poorly predictive. ICT tests achieved high sensitivity (97.9%) but many cases indicated as positive by ICT tests were negative by microscopy. Further analysis of these cases in Trial I indicated that ICT tests were detecting low-level parasitaemias missed by microscopy, and that local microscopy had poor accuracy. ICT tests were well accepted and accurately performed by barangay health workers. CONCLUSION: These tests meet a strong desire in the community for blood-based diagnosis and may increase the compliance and treatment-seeking behaviour of patients.

Adult↗
PubMed2000

Dual role of PKC in modulating pharmacomechanical coupling in fetal and adult cerebral arteries.

This study tested the hypothesis that protein kinase C (PKC) has dual regulation on norepinephrine (NE)-mediated inositol 1,4, 5-trisphosphate [Ins (1,4,5)P(3)] pathway and vasoconstriction in cerebral arteries from near-term fetal ( approximately 140 gestational days) and adult sheep. Basal PKC activity values (%membrane bound) in fetal and adult cerebral arteries were 38 +/- 4% and 32 +/- 4%, respectively. In vessels of both age groups, the PKC isoforms alpha, beta(I), beta(II), and delta were relatively abundant. In contrast, compared with the adult, cerebral arteries of the fetus had low levels of PKC-epsilon. In response to 10(-4) M phorbol 12,13-dibutyrate (PDBu; PKC agonist), PKC activity in both fetal and adult cerebral arteries increased 40-50%. After NE stimulation, PKC activation with PDBu exerted negative feedback on Ins(1,4,5)P(3) and intracellular Ca(2+) concentration ([Ca(2+)](i)) in arteries of both age groups. In turn, PKC inhibition with staurosporine resulted in augmented NE-induced Ins(1,4,5)P(3) and [Ca(2+)](i) responses in adult, but not fetal, cerebral arteries. In adult tissues, PKC stimulation by PDBu increased vascular tone, but not [Ca(2+)](i). In contrast, in the fetal artery, PKC stimulation was associated with an increase in both tone and [Ca(2+)](i). In the presence of zero extracellular [Ca(2+)], these PDBu-induced responses were absent in the fetal vessel, whereas they remained unchanged in the adult. We conclude that, although basal PKC activity was similar in fetal and adult cerebral arteries, PKC's role in NE-mediated pharmacomechanical coupling differed significantly in the two age groups. In both fetal and adult cerebral arteries, PKC modulation of NE-induced signal transduction responses would appear to play a significant role in the regulation of vascular tone. The mechanisms differ in the two age groups, however, and this probably relates, in part, to the relative lack of PKC-epsilon in fetal vessels.

Animals↗
PubMed1999

Biosynthesis of mannosylglycerate in the thermophilic bacterium Rhodothermus marinus. Biochemical and genetic characterization of a mannosylglycerate synthase.

The biosynthetic reaction scheme for the compatible solute mannosylglycerate in Rhodothermus marinus is proposed based on measurements of the relevant enzymatic activities in cell-free extracts and in vivo (13)C labeling experiments. The synthesis of mannosylglycerate proceeded via two alternative pathways; in one of them, GDP mannose was condensed with D-glycerate to produce mannosylglycerate in a single reaction catalyzed by mannosylglycerate synthase, in the other pathway, a mannosyl-3-phosphoglycerate synthase catalyzed the conversion of GDP mannose and D-3-phosphoglycerate into a phosphorylated intermediate, which was subsequently converted to mannosylglycerate by the action of a phosphatase. The enzyme activities committed to the synthesis of mannosylglycerate were not influenced by the NaCl concentration in the growth medium. However, the combined mannosyl-3-phosphoglycerate synthase/phosphatase system required the addition of NaCl or KCl to the assay mixture for optimal activity. The mannosylglycerate synthase enzyme was purified and characterized. Based on partial sequence information, the corresponding mgs gene was identified from a genomic library of R. marinus. In addition, the mgs gene was overexpressed in Escherichia coli with a high yield. The enzyme had a molecular mass of 46,125 Da, and was specific for GDP mannose and D-glycerate. This is the first report of the characterization of a mannosylglycerate synthase.

Amino Acid Sequence↗
PubMed1998

[CHARGE association].

Posterior choanal atresia is a congenital malformation which can occur isolated or in combination to additional malformations. In CHARGE association the other anomalies are: coloboma, heart disease, retarded development/growth or central nervous system abnormalities, genital hypoplasia or hypogonadism and ear abnormalities or deafness. The authors present three cases of CHARGE association and they also review the clinical findings required for the diagnosis.

Abnormalities, Multiple↗
PubMed1997

Dyssegmental dysplasia: a case report of a Rolland-Desbuquois type.

Two different forms of dyssegmental dysplasia, mild and severe, can be distinguished on clinical, radiographic and chondro-osseous morphologic grounds. The milder Rolland-Desbuquois type is frequently characterised by survival beyond the newborn period. The lethal Silverman-Handmaker type has distinctive and more severe findings. In this paper, a rare case of the Rolland-Desbuquois type is presented. The case is unusual because although it was the milder form, the child died on the 10th day of life.

Abnormalities, Multiple↗
PubMed1997

Isoform-specific effects of apolipoproteins E2, E3, and E4 on cerebral capillary sequestration and blood-brain barrier transport of circulating Alzheimer's amyloid beta.

Cerebral capillary sequestration and blood-brain barrier (BBB) permeability to apolipoproteins E2 (apoE2), E3 (apoE3), and E4 (apoE4) and to their complexes with sA beta(1-40), a peptide homologous to the major form of soluble Alzheimer's amyloid beta, were studied in perfused guinea pig brain. Cerebrovascular uptake of three apoE isoforms was low, their blood-to-brain transport undetectable, but uptake by the choroid plexus significant. Binding of all three isoforms to sA beta(1-40) in vitro was similar with a K(D) between 11.8 and 12.9 nM. Transport into brain parenchyma and sequestration by BBB and choroid plexus were negligible for sA beta(1-40)-apoE2 and sA beta(1-40)-apoE3, but significant for sA beta(1-40)-apoE4. After 10 min, 85% of sA beta(1-40)-apoE4 taken up at the BBB remained as intact complex, whereas free sA beta(1-40) was 51% degraded. Circulating apoE isoforms have contrasting effects on cerebral capillary uptake of and BBB permeability of sA beta. ApoE2 and apoE3 completely prevent cerebral capillary sequestration and blood-to-brain transport of sA beta(1-40). Conversely, apoE4, by entering brain microvessels and parenchyma as a stable complex with sA beta, reduces peptide degradation and may predispose to cerebrovascular and possibly enhance parenchymal amyloid formation under pathological conditions.

Amino Acid Sequence↗
PubMed1997

Thermonema rossianum sp. nov., a new thermophilic and slightly halophilic species from saline hot springs in Naples, Italy.

Six slightly halophilic, thermophilic bacterial strains were isolated from saline hot springs along the Bay of Naples, Italy. These strains produce bright yellow colonies and have a filamentous morphology and an optimum growth temperature of about 60 degrees C. Lipid composition and 16S ribosomal DNA sequence analyses showed that these strains belong to the genus Thermonema, a member of the cytophaga-flavobacter-bacteroides phylum. Growth was observed in medium containing 1 to 3% NaCl. The DNA G + C content was 50.9 mol%. DNA-DNA hybridization studies showed that these strains represent a new species of the genus Thermonema. We propose that strain NR-27T (T = type strain) and the other strains represent a new species, Thermonema rossianum. Strain NR-27 (= DSM 10300) is the type strain of this species.

Bacteria, Aerobic↗
PubMed1996

Laparoscopic cholecystectomy in the third trimester of pregnancy.

Laparoscopic cholecystectomy has become the method of choice for symptomatic cholelithiasis. Laparoscopic cholecystectomy during pregnancy is also becoming more accepted, as illustrated by several recent publications on this subject. In the third trimester, however, laparoscopic cholecystectomy has been less commonly attempted, with only a few case reports. We present a series of four patients who underwent laparoscopic cholecystectomy during the third trimester of pregnancy without complication. We describe a safe and effective technique for this procedure, and review the literature on this topic.

Adolescent↗
PubMed1995

[Growth and development of children with low birth weight at their first birthday].

The aim of this prospective study was to evaluate the effect of low birthweight on growth and development at one year of age, in a cohort of infants born between March 1992 and March 1993 at Hospital de Famalicão. Information was obtained from 199 children, 89 low birthweight cases and 110 born with a normal (> or = 2500 g) weight. The infant mortality rate (56 vs 9 per 1000), the frequency of growth (32% vs 4%, p = 0.0000003) or developmental delay (30% vs 11%, p = 0.002) were significantly higher in low birthweight babies. However, all cases of developmental delay corresponded to minor impairments. At age one, children born with a normal weight presented mean higher values for weight (10.0 +/- 1.1 kg vs 9.2 +/- 1.2 kg; p = 0.000005), length (74.2 +/- 7.1 cm vs 72.9 +/- 3.1 cm, p = 0.0006) and head circumference (46.4 +/- 1.9 cm vs 45.8 +/- 1.6 cm; p = 0.004). Prenatal characteristics such as the planning of the pregnancy, gestational birth weight, diseases during the pregnancy, gestational age or twining, significantly affected development at one year of age, showing that delays can be prevented before a child is born. In addition, post-natal exposures, such as home conditions, energy and nutrient intake, or coping with vaccination schedules and the occurrence of diseases during the neonatal and post-neonatal periods were significantly associated to developmental delay.(ABSTRACT TRUNCATED AT 250 WORDS)

Child Development↗
PubMed1989

Local control and survival of Ewing's sarcoma in children with radiotherapy and chemotherapy without radical surgery.

The present study was undertaken in 27 children with localized Ewing's sarcoma treated at our hospital. In 9 cases the lesion was central and in 18 peripheral. Treatment consisted of: 1) Chemotherapy with 6 drugs (vincristine, cyclophosphamide, methotrexate, bleomycin, dactinomycin and doxorubicin) for one year in all patients; 2) Radiotherapy in 24 patients at a dose of 30-40 Gy in the entire bone with a booster dose of 10-15 Gy in the lesion. In 7 patients debulking surgery was performed followed by irradiation. Two cases with tumor in expendable bones and one with extensive destructive lesion in the tibia underwent radical surgery. One patient suffered local recurrence (femur) and 6 developed distant metastases. The remaining 20 (74%) patients were alive and tumor-free after follow-up periods of 17-80 months. Among the 12 patients with extremity lesions who were alive, 7 (58%) had minimal or mild treatment sequelae, 2 moderate, and 3 severe sequelae but no amputation has been required. Our study shows that local control can be achieved in almost all patients without radical surgery and with acceptable extremity function in the majority.

Adolescent↗
PubMedDate not supplied

[Adenoid cystic carcinoma of the breast].

OBJECTIVE: To review the clinical presentation and imaging findings of adenoid cystic carcinoma (ACC). MATERIAL AND METHODS: We performed a retrospective study of the period between January 1990 and July 2004, comprising five cases of ACC of the breast, all in women, among 4,036 malignant lesions diagnosed (0.12%). We reviewed the available imaging studies (mammography in all five cases, ultrasound in four, and magnetic resonance in one). We also reviewed the clinical presentation and evolution in all patients. RESULTS: Three patients presented with palpable lesions. Mammographic findings consisted of irregular, ill-defined nodules in three cases, a well-defined rounded nodule in one, and an asymmetrical density in the other. No microcalcifications were observed in any case. Ultrasound examination showed ill-defined polylobulated nodules in three cases and a well-defined, rounded nodule with small cysts inside in the remaining case that showed intense vascularization in the Doppler study. The only case studied by magnetic resonance was seen as a rounded nodule that showed heterogeneous contrast uptake, well-defined margins, and an enhancement curve considered highly suspicious for malignancy. Treatment was tumorectomy together with radiotherapy in all cases. Four patients remain asymptomatic at present (mean follow-up = 64 months) and one presented lung and liver metastes twelve years after the diagnosis of ACC. CONCLUSION: ACC is an uncommon breast tumor with varied radiologic appearance, although moderately or highly suspicious lesions predominate. We consider the absence of microcalcifications in these tumors to be noteworthy. The prognosis is generally good, although the possibility of remote metastasis exists.

Aged↗
PubMedDate not supplied

[Small for gestational age newborn infants. The effect of standard curves of birth weight on the calculation of the prevalence and of the risk factors].

Sampling decisions, statistical methods and criteria for dating pregnancy all influence birth-weight percentiles and the ability to classify a newborn as growth retarded or small for date. Consequently the prevalence of small for date, the type and the magnitude of risk factors associated with this condition, and the evaluation of preventive interventions are dependent on the standards used. In this study we established birthweight standards for sex and gestational age (36 to 41 weeks) in a sample of 7518 singleton newborns delivered from 1989-92 at Famalicão Hospital. Later, these reference percentiles were applied to a sample of 2210 to calculate the prevalence of small for date, to evaluate associated risk factors, and to compare these estimates with those obtained using Thompson or Lubchenco published charts. The prevalence of small for gestational age was significantly higher using local standards (9.9 or 10.0%) when compared with those obtained using Thompson (8.8%, p < 0.005) or Lubchenco (4.4%, p < 0.005) percentiles. However, the risk factors identified and the magnitude of the point estimates for odds ratios were similar regardless of the reference percentiles. This study shows a significant misclassification of newborns as small or adequate for gestational age that may affect individual prognosis, but this is not reflected in the type and the importance of detected risk factors at a group level.

Birth Weight↗
PubMedDate not supplied

A study of the capacity of soils to induce nodules in Alnus glutinosa (L.) Gaertn. and Myrica gale L., with special reference to the specificity of the endophytes.

One hundred soil samples from sites in North, Centre and West of Spain were examined for their capacity to induce nodules in alder (Alnus glutinosa) and bog myrtle (Myrica gale). Soils from A. glutinosa communities particularly from places where Myrica was absent, were checked for their infectivity towards M. gale. There was a good correlation between the results, since there was not one single sample which could induce nodules in Myrica which did not do the same in alder. The nodules formed on M. gale plants grown in soils collected from alder habitats showed acetylene-reducing activity at a level comparable to that described in the literature, in the case of other Myrica species. Considering together the results now obtained and in previous work, the possibility of cross-inoculation between M. gale and A. glutinosa, is again put forward and it is thus held that no specificity can be assigned, for the time being, to the respective endophytes.

Nitrogen Fixation↗